1. Field of the Invention
The present invention pertains to the field of Wheelchairs. In general, such devices have been designed to transport individuals with physical problems which preclude their ability to move about easily through the use of their legs or who may temporarily need assistance. Such patients may be debilitated in many different ways and a variety of devices have been designed to overcome many of the limitations that such patients have. It is also recognized that many such patients are unable to move themselves between the wheelchair and their bed.
Standard hand-operated wheelchairs are limited in their ability to facilitate easy transfer of patients from the chair to another surface. This is due to the size of the wheel which is higher than the normal seat level. Additionally, many of these chairs have arm rests which are fixed in position.
Many such patients have elderly or otherwise infirm care-givers who have difficulty in accomplishing or aiding such transfers. The present invention aims to facilitate the transfer of patients from the chair to other surfaces through many innovative features.
2. Prior Art
U.S. Pat. No. 5,161,812 invented by John DeWeese discloses his invention for an elevating wheelchair operated by hydraulics with the addition of commode features. The lifting mechanism is a pair of collapsible links spread or collapsed by a hydraulic cylinder. The vertical motion is guided by a set of vertical restraining guide tubes. His implementation has raisable arms, a wheel brake, and a pin lock for upper position safety.
U.S. Pat. No. 5,046,571, invented by Bjorn Kullerud of Norway presents an electrically operated lifting mechanism. It is a very specific mechanism for raising and lowering a patient. It does not show nor claim a backrest or any other trunk support for a patient in the seated position.
U.S. Pat. No. 4,934,723, invented by Edward Dynars, shows another implementation of a raising wheelchair. It claims several motive sources including pneumatic, hydraulic, and springs. It offers methods of actuation in general and by lifting the arm. The chair is raised by lowering and pivoting outward a set of feet to engage the floor and raise the chair. This chair is intended to bring the patient to the eye level height of a standing person while remaining seated.
U.S. Pat. No. 4,862,997, invented by Kenneth Eberle, shows another implementation of a raisable wheelchair for essentially the same purposes as the Dynars patent. Its main difference is that the seat portion raises the patient while the wheels remain engaged with the floor. It uses electrical means to raise the seat and trunk support portions.
The present invention addresses the above limitations in several ways.